src/gromacs/mdrunutility/multisim.h

   1 /*
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   4  * Copyright (c) 2018,2019, by the GROMACS development team, led by
   5  * Mark Abraham, David van der Spoel, Berk Hess, and Erik Lindahl,
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  35 /*! \libinternal \file
  36  *
  37  * \brief Declares the multi-simulation support routines.
  38  *
  39  * \author Mark Abraham <mark.j.abraham@gmail.com>
  40  * \inlibraryapi
  41  * \ingroup module_mdrunutility
  42  */
  43 #ifndef GMX_MDRUNUTILITY_MULTISIM_H
  44 #define GMX_MDRUNUTILITY_MULTISIM_H
  45
  46 #include <memory>
  47 #include <string>
  48
  49 #include "gromacs/utility/arrayref.h"
  50 #include "gromacs/utility/gmxmpi.h"
  51 #include "gromacs/utility/mpiinplacebuffers.h"
  52
  53 /*! \libinternal
  54  * \brief Coordinate multi-simulation resources for mdrun
  55  *
  56  * \todo Change this to class
  57  */
  58 struct gmx_multisim_t
  59 {
  60     //! Default constructor
  61     gmx_multisim_t();
  62     /*! \brief Constructor useful for mdrun simulations
  63      *
  64      * Splits the communicator into multidirs.size() separate
  65      * simulations, if >1, and creates a communication structure
  66      * between the master these simulations.
  67      *
  68      * Valid to call regardless of build configuration, but \c
  69      * multidirs must be empty unless a real MPI build is used. */
  70     gmx_multisim_t(MPI_Comm                         comm,
  71                    gmx::ArrayRef<const std::string> multidirs);
  72     //! Destructor
  73     ~gmx_multisim_t();
  74
  75     //! The number of simulations in the set of multi-simulations
  76     int                                 nsim              = 1;
  77     //! The index of the simulation that owns this object within the set
  78     int                                 sim               = 0;
  79     //! The MPI Group between master ranks of simulations, valid only on master ranks.
  80     MPI_Group                           mpi_group_masters = MPI_GROUP_NULL;
  81     //! The MPI communicator between master ranks of simulations, valid only on master ranks.
  82     MPI_Comm                            mpi_comm_masters  = MPI_COMM_NULL;
  83     //! Communication buffers needed if MPI_IN_PLACE isn't supported
  84     mpi_in_place_buf_t *                mpb               = nullptr;
  85 };
  86
  87 //! Calculate the sum over the simulations of an array of ints
  88 void gmx_sumi_sim(int nr, int r[], const gmx_multisim_t *ms);
  89
  90 //! Calculate the sum over the simulations of an array of large ints
  91 void gmx_sumli_sim(int nr, int64_t r[], const gmx_multisim_t *ms);
  92
  93 //! Calculate the sum over the simulations of an array of floats
  94 void gmx_sumf_sim(int nr, float r[], const gmx_multisim_t *ms);
  95
  96 //! Calculate the sum over the simulations of an array of doubles
  97 void gmx_sumd_sim(int nr, double r[], const gmx_multisim_t *ms);
  98
  99 /*! \brief Return a vector containing the gathered values of \c
 100  * localValue found on the master rank of each simulation. */
 101 std::vector<int> gatherIntFromMultiSimulation(const gmx_multisim_t *ms,
 102                                               int                   localValue);
 103
 104 /*! \brief Check if val is the same on all simulations for a mdrun
 105  * -multidir run
 106  *
 107  * The string name is used to print to the log file and in a fatal error
 108  * if the val's don't match. If bQuiet is true and the check passes,
 109  * no output is written. */
 110 void check_multi_int(FILE *log, const gmx_multisim_t *ms,
 111                      int val, const char *name,
 112                      gmx_bool bQuiet);
 113 /*! \copydoc check_multi_int() */
 114 void check_multi_int64(FILE *log, const gmx_multisim_t *ms,
 115                        int64_t val, const char *name,
 116                        gmx_bool bQuiet);
 117
 118 #if GMX_DOUBLE
 119 //! Convenience define for sum of reals
 120 #define gmx_sum_sim   gmx_sumd_sim
 121 #else
 122 //! Convenience define for sum of reals
 123 #define gmx_sum_sim   gmx_sumf_sim
 124 #endif
 125
 126 //! Are we doing multiple independent simulations?
 127 static bool inline isMultiSim(const gmx_multisim_t *ms)
 128 {
 129     return ms != nullptr;
 130 }
 131
 132 /*! \brief Return whether this rank is the master rank of a
 133  * simulation, using \c ms (if it is valid) and otherwise \c
 134  * communicator */
 135 bool findIsSimulationMasterRank(const gmx_multisim_t *ms,
 136                                 MPI_Comm              communicator);
 137
 138 //! Are we the master simulation of a possible multi-simulation?
 139 bool isMasterSim(const gmx_multisim_t *ms);
 140
 141 /*! \brief Are we the master rank (of the master simulation, for a multi-sim).
 142  *
 143  * This rank prints the remaining run time etc. */
 144 bool isMasterSimMasterRank(const gmx_multisim_t *ms,
 145                            bool                  isMaster);
 146
 147 //! Make a barrier across all multi-simulation master ranks
 148 void multiSimBarrier(const gmx_multisim_t *ms);
 149
 150 #endif